1. Field of the Invention
This invention relates, in general, to valves, and more particularly to butterfly valves which are self-locked into position.
2. Description of the Prior Art
Butterfly valves of many different shapes and for a multitude of purposes are well-known in the art. Generally, the valves comes as individual units including a tubular housing which is then connected to pipes or other apparatus. Valve discs may be supported by single shafts, C. H. Auger, U.S. Pat. No. 2,114,168, or by a pair of shafts or stems, S. R. Puffer, U.S. Pat. No. 2,282,825 and C. N. Roswell, U.S. Pat. No. 2,552,117. Discs are attached to the shaft by welding, or more commonly by screws, A. Petersen, U.S. Pat. No. 2,754,969. The problems associated with the installation of disc and shaft into an existing pipe and securing the disc to the shaft are obvious.